Outcomes associated with different antithrombotic strategies after Amulet left atrial appendage occlusion (LAAO) are not well described.

This analysis compared outcomes from patients discharged on dual antiplatelet therapy (DAPT) versus single antiplatelet therapy (SAPT) or oral anticoagulation (OAC) following Amulet implant in the EMERGE LAA post-approval study.

Patients with a successful Amulet implant and discharged from the hospital between August 14, 2021 and December 15, 2023 and entered into the National Cardiovascular Data Registry (NCDR) LAAO Registry were included. A safety endpoint of all-cause death, stroke, major bleeding, or systemic embolism and effectiveness endpoint of ischemic stroke, systemic embolism, or cardiovascular death were assessed through 6 months as well as major adverse events.

A total of 11,445 patients were included in this analysis with 9355 discharged on DAPT (81.7 %), 606 on SAPT (5.3 %), and 1484 on OAC (13.0 %). Patients in the SAPT group had more comorbid conditions and were at the greatest bleeding risk pre-Amulet implant. At 45-days, clinically relevant closure (≤3 mm peri-device leak) was achieved in >95 % of all patients. At 6 months, the safety endpoint rates were 8.8 %, 7.0 %, and 7.0 % in the DAPT, SAPT, and OAC groups, respectively (p = 0.045) and effectiveness endpoint rates were 2.1 %, 1.6 %, and 1.7 % in the DAPT, SAPT, and OAC groups, respectively (p = 0.511). Despite higher baseline bleeding risk, the SAPT group had numerically lower bleeding rates than the DAPT group through 6 months (DAPT 4.8 % vs. SAPT 3.9 %; HR 1.23 [0.78, 1.95]) with no difference in device-related thrombus rates (DAPT 0.8 % vs. 0.8 % SAPT; HR 0.91 [0.33, 2.50]). However, after adjusting for differences in baseline characteristics, no significant differences (p > 0.05) were noted for any clinical events between the three medication groups at 45 days or 6 months.